Mandrel positioning device for tube mills and the like



Dec. 26, 1950 J. w. OFFUTT MANDREL POSITIONING DEVICE FOR TUBE MILLS AND THE LIKE Filed Jan. 11. 1945 3 Sheets-Sheet 1 INVENTOR.

2,535,949 E}; FOR

Dec. 26, 1950 J. w. OFFUTT MANDREL POS 10mm; DEV

TUBE MI AND THE 3 Sheets-Sheet 5 Filed Jan. 11. 1945 \1 Y v w\ W/ZL INVENTOR: JOHN W 0/7077;

Patented Dec. 26, 1950 MANDREL POSITIONING DEVICE FOR TUBE MILLS AND THE. LIKE John W. Oflutt, Ellwood City, Pa., assignor to National Tube Company, a corporation of New Jersey Application danuar y 11, 1945, Serial No. 572,283

3 Claims.

This invention relates to pipe or tube mills employing a rotatable mandrel bar, and more particularly to improvements in the mandrel positioning devices used therein.

In rolling seamless pipe or tubing in conventional mills, a mandrel plug is held between the metal working rolls by a mandrel bar. Since the workpiece is telescoped over the mandrel bar during the rolling operation, it is necessary to withdraw the mandrel bar from the metal Working position in order to remove the workpiece therefrom. Means are provided to rapidly withdraw the mandrel bar and to reposition it after the workpiece is removed.

In addition to the foregoing mandrel movement, it is necessary to provide a longitudinal adjustment of the mandrel bar to position accurately the mandrel plug between the metal working rolls. Heretofore, such adjustment has been effected by an adjusting nut combined with the thrust bearing assembly, to which the rear end of the mandrel bar is attached. Rotation of this nut moves the thrust bearing within its housing and the attached mandrel bar relative to the stationary latch housing of the mill to thereby position the mandrel bar and plug relative to the metal working rolls.

It is accordingly an object of this invention to provide a seamless tube mill mandrel bar adjustment which permits the use of a thrust is possible in conventional designs.

It is a further object to provide an adjustment for mandrel bars which is rugged and simple in design and adapted to conventional tube mills.

The foregoing and further objects will be apparent from the specification and drawings, wherein:

Figure 1 is a plan view of a seamless pipe or tube mill embodying my improved mandrel adjustment device;

Figure 2 is an enlarged plan view of the mandrel bar carriage and the associated adjusting members;

Figure 3 is an enlarged sectional elevation of the same taken on line IIIIII of Figure 2; and

Figure 4 is a cross section on line IVIV of Figure 3.

Referring more particularly to the drawings,

bearing of more substantial construction than the numeral 2 designates a pair of metal working rolls between which a mandrel plug 5 is held in metal working position by a mandrel bar 4. After a tubular workpiece A has been completely rolled between the metal working rolls 2and over the intermediately disposed mandrel plug mandrel bar 4, it is removed from the mill by withdrawing the mandrel bar and moving the workpiece to an adjacent skidway 6 by conventional kick-off arms (not shown). In accordance with conventional design, the mandrel bar 4 is carried by a'carriage I5 which reciprocates on an elongated frame or slideway 9 forming part of the outlet bed of the mill. 1

The outlet bed is also provided with a pair of suitably spaced sheaves l0, one of which is driven by a reversible motor (not shown). A cable l2 connects the sheaves for conjoint rotation andthe ends thereof are attached to the mandrel bar carriage [5. Thus by operating the reversible motor (not shown), the mandrel bar carriage l5 and the attached mandrel bar. 4, are moved toward or away from the mill for the purposes above described.

A housing 20 is vertically disposed on eithe side of the outlet bed of the mill adjacent the mandrel bar carriage l5 when it is in its forward or metal rolling position and extends thereabove as shown in Figures 2 and 3. A shaft 22 is journaled in the latch housing 20 transversely thereof and embodies a pair of latch members 23 adjacent the latch housing 213.

A trunnion mounted. fluid actuated cylinder 25 is carried by the housing 20 at one side and rearwardly of the shaft22 and somewhatelevated thereabove. The exposed end of the piston is pivotally connected as at 2% tea crank arm .21 keyed or otherwise secured to the shaft 22.

Thus it is seen that energization of the fluid actuated cylinder 25 will partially rotate the shaft 22 so as to raise the latch members 23 out of engagement or lower them into engagement with suitable abutment plates on a thrust hearing saddle, hereinafter described.

The mandrel bar carriage [5 comprises a thrust bearing housing having a thrust bearing 3| positioned and held therein by nuts 32. An up wardly projecting box-like lug is integrally mounted on top of the bearing housing 30 and is provided with recesses 36 in the forward and rearward faces thereof. The housing 30 is also provided with outwardly extending integral side flanges 40 having upturned ends 41 forming slideways 42 on the upper surfaces of the flanges. The lower sides of the projections 40 are adapted to engage the lower ways 9 of the outlet bed of the mill.

Reciprocably mounted on the ways 42 of the housing 3|] is a saddle 45 which has upwardly extending interiorly threaded lugs 46, at either :52 on the saddle 45.

end thereof, which are in axial alignment with the recesses 36 in the lug 35. Disposed in the lugs 46 are adjusting screws 28, the inner ends of which are received in the recesses 36 in the lug and thereby lock the saddle 45 in position.

A pair of recesses 5!] is provided on the upper surface of the side members of the saddle intermediate the ends thereof and the forward sides of the recesses are provided with angularly disposed bearing plates 52. The angularity of the plates 52 and the lower ends of latch members 23 is such that axial thrust applied to the bearing 3! during rolling operations is transmitted through the housing 3t,:adjusting screws 48 and saddle d5, holds the housing 353 and the saddle 45 rigidly together, and also holds the housing 36 firmly on the slideways 9.

In operation, the reversible motor (not shown) is operated to position the plug 5 intermediate the rolls 2. Cylinder is then activated to lower the latch so that :it engages the plates This prevents rearward axialmovement of the plug 5 and bar 4. Accurate adjustment of the plug 5 between the .rolls 2 is then eiTected by turning the screws '68. After a workpiece A has been rolled and telescoped over the mandrel bar 4, the mandrel bar is retracted to remove it from the workpiece A by operating the cylinder 25 to lift the latch 23. The reversible "motor (not shown) is then energized to :move the mandrel carriage 15 away from the mill. ASTSOOIl "as the workpiece has been removed, the fore going operations are repeated to reposition the plug intermediate the rolls and to remove telescoped workpieces from the mandrel bar. ever, it is not necessary to readjust the plug '5 by turning the screws 48 .for each workpiece since this may need only be done from time to time as it becomes necessary.

While I have shown and described one specific embodiment of my invention, it will be understood that'this embodiment is merely for the purpose of illustration and description and that various other forms may be devised within the scope of my invention, as defined in the appended claims.

I claim:

1.1n a seamless pipe or tube mill having a reciproca'ble mandrel bar and. an outlet bed 'including slideways for reciprocating said mandrel bar, a thrust bearing housing supporting said mandrel bar, oppositely disposed longitudinally Howiii extending flanges on said housing, the lower surfaces of said flanges adapted to slide on said slideways and the upper surfaces thereof forming secondary slideways, an adjustable saddle mounted on said housing and adapted to ride on said secondary slideways and retractable means engaging said saddle to hold said mandrel bar against longitudinal thrust.

2. In a seamless pipe or tube mill having a 'reciprocable mandrel bar and an outlet bed including slideways for reciprocating said mandrel bar, :a thrust bearing housing supporting said mandrel bar, oppositely disposed longitudinally extending .flan'geson said housing, the lower surfaces thereof adapted to slide on said slideways and the uppersuriaces thereof forming secondary slideways, an upwardly extending lug on said housing, a saddle adapted to ride on said secondary slideways, at least one adjusting screw engaging said saddle and said lug to position said saddle with respect to said housing and retractable uneans engaging said saddle :to hold said mandrel bar against longitudinal thrust.

3. In a seamless pipe or tube mill .having .a reciprocable mandrel bar and anoutlet'bed including slideways for reciprocating the mandrel bar, .a thrust ibearing housing supporting said mandrel bar, a pair of oppositely disposed verticallyspaced slideways'on said housing, the lower of said slideways adapted to ride on .the first mentioned slideways forming part of the :outlet bed "of the mill, an adjustable saddle mounted on-said housingaand adapted to vride on the upper of said pair of slideways and a retractable latch adapted :to engage said saddle to hold said mandrel bar :againstJOngitudinal thrust :and to be disengaged therefrom to permit said mandrel bar to be reciprocated.

JOHN W. OFFUT'I.

'REFFEEEN CES CITED The "following references are of record in the file of this patent:

UNITED STATES PATENTS 

